334 CALIFOENIA ACADEMY OF SCIENCES. 



small, flattened, subeqiial, equidistant, revolving ribs, five on the upper whorls; interspaces orna- 

 mented by fine, oblique, incremental lines; base of body-whorl nearly flat, and ornamented with 

 numerous fine, revolving lines, which become coarser near umbilicus; suture deeply impressed, dis- 

 tinct; aperture circular; columella somewhat arcuate; umbilicus small, groove-like; outer lip sharp, 

 nacreous layer on inner lip. 



Dimensions. — Alt. 5.8 mm.; lat. 8 mm.; defl. 67 degrees. 



Somewhat resembles Solariella peramabilis, but may be distingiiislied by smaller 

 umbilicus; flatter, finer sculptured base; whorls less flattened above and finer sculp- 

 tured, both spiral and transverse. Dr. Dall pronounced the Pliocene specimen a 

 variety of M. 'pupilla. 



Found in Pliocene at Deadman Island; two specimens, one of which is figured, 

 and is now in the collection of Delos Arnold. Found also in the Pleistocene at 

 the bath-house, Santa Barbara. 



Living. — Alaska to Catalina Island, rare at latter place (Cooper). 



Pleistocene. — Santa Barbara (Cooper; Arnold). 



Pliocene. — San Pedro (Arnold). 



Genus Solariella S. Wood. 



Shell thin, globular-conical; generally with wide crenated umbilicus; whorls rounded, 

 sculptured; aperture rounded; lip sharp, smooth. 



Solariella peramabilis Cpr. is a characteristic species. 



390. Solariella cidaris A. Adams. 

 Plate VII, Fig. 11. 



Margarita cidaris A. Ad., Cpr., Brit. Assn. Rept., 1863, p. 653. Cpr., Ann. Mag. Nat. Hist., 3rd 



Sen, Vol. XIV, 1864, p. 426; Vol. XV, 1865, p. 29. Cooper, 7th Ann. Rept. Cal. St. 



Min., 1888, p. 249 (young); ^= Solariella oxybasis Dall {fide Cooper, Bull. No. 4, Cal. 



St. Min. Bureau, Part 3, 1S94, p. 27). 

 Turcicula cidaris (A. Ad.) Cpr., Tryon, Man. Conch., Vol. XI, p. 331, 1889. 

 Solariella cidaris A. Ad., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 202, Pi. XXII, 



fig- 4- 



Shell conical; spire elevated, subacute; whorls six to seven; four upper whorls only slightly 

 conve.x; lower whorls very convex; surface ornamented with spiral rows of nodes which grade into 

 nodose ribs on the lower side of the body-whorl; suture deeply impressed; aperture circular; outer 

 lip thin; inner lip and columella enameled, the incrustation completely obscuring the small umbilicus 

 in most specimens. 



Dimensions. — Alt. 40 mm.; lat. 33 mm.; body-whorl 26.5 mm.; aperture 13 mm.; defl. 

 66 degrees. 



The specimen described and figured is an exceptionally large one, the average 

 altitude being only 18 mm. Identification by Dr. Dall. 



Rare in the Pliocene; only about a dozen specimens found, and all of these 

 from the Pliocene of Deadman Island. According to Dr. Cooper, San Marcial is on 



